A conventional knife changing system for cutting center machine employs a chain which has a plurality of sockets each of which receives a knife therein. The chain rotates about a center shaft so as to move a knife to be used to a desired position so that a knife picking device picks the knife and installs the knife to the engaging means on a driving shaft. Although 30 knifes can be connected to the chain for the use of the users, however, each knife is so heavy so that the chain needs a huge power to rotate it and the space needs a lot of space so that the chain and the knifes can be retained therein. If the chain travels a long distance, the position of the knifes relative to the chain could slightly change due to gravity, and it consumes energy. Of more importance is that when changing the knifes, the knife picking device has to wait for the chain and this takes time. For example, if the knife #30 is to be picked, then the chain has to rotate almost a complete circle to allow the knife #30 be shifted to the position where is suitable for the picking device to proceed the knife engaging process. If a job has to use 20 to 30 knifes, the time consumed in knifes changing is significant which will increase the cost of manufacturing.
The present invention intends to provide a knife picking device and a knife receiving unit, wherein the knife picking device can be moved along two axes which are perpendicular with each other so as to quickly arrive the position where the desired knife is located. Accordingly, the knife receiving unit may receive a lot of knifes within a small space and there will be not necessary to include a large transportation system to move or shift the knifes in the knife receiving unit.
The present invention has arisen to mitigate and obviate the disadvantages of the conventional knife picking device and the conventional knife receiving unit.